I have a Verlicchi aluminium swingarm thats needs a little welding job. Does anyone know what type of aluminium that is used in this?

Have access to a great welder, but want to give him info if there are things he need to consider before he starts.

I assume you are looking for a filler rod as near to the original swing arm material as possible. I have asked the same question to so many welding suppliers over the years and always got the same answer.
"Sorry sir, you simply can't weld compressed bus tickets" !!